This application claims Paris Convention priority of DE 199 18 527 filed Apr. 23, 1999 the complete disclosure of which is hereby incorporated by reference.
The invention concerns a packaging machine comprising a transfer device for inserting a product into a package, in particular, a folding box, and with a circulating leaflet-transporting device comprising a plurality of tong-like holders, each receiving one leaflet and which can dispose the leaflet between the product and the package in the region of the transfer device for insertion thereof, together with the product, into the package, wherein, in the region of the transfer device, a stop is disposed in the transport path of the tong-like holder for opening the holder to release the leaflet.
When packaging products using a transfer device in a packaging machine, the motions of a first circulating transport device for the package, e.g. a so-called folding box chain, is usually synchronized with that of a second circulating transport device for the products, e.g. a so-called product chain, in such a manner that the product can be inserted at a side of the folding box, transverse to the direction of motion of the chains. With certain products, e.g. medication, a leaflet or package insert must be added to the package. Towards this end, a further circulating transport device is provided supporting a plurality of tong-like holders, each of which receives and clamps a leaflet. A leaflet to be inserted into the package is moved in the transport device and disposed between the product and the folding box and is pushed by the product, during lateral inserting motion thereof, into the folding box. As soon as the product abuts against the leaflet, the tong-like holder must be opened to release the leaflet. Towards this end, the tong-like holder abuts, during its transport motion, against a stationary stop wedge disposed proximate to the transfer device. The stop wedge interacts with the holder upon abutment thereof to open the tong arms and release the leaflet.
Packaging machines are sometimes subject to minor malfunctions which can cause temporary, discontinuous delivery of folding boxes to the folding box chain, wherein one or several sections of the folding box chain are not occupied by folding boxes. This absence of a folding box is recognized by a sensor mechanism to stop insertion of the product. When abutting against the stop wedge, the tong-like holder opens to release the leaflet. The leaflet should then fall out through the bottom of the packaging machine. However, it has turned out that the released leaflet can inadvertently remain in the transfer station or can move in an uncontrolled manner through the packaging machine leading to operational disturbances thereof and possibly to temporary stoppage which must usually be dealt with manually and which is therefore time consuming and expensive.
It is the underlying purpose of the invention to provide a packaging machine of the mentioned type which reliably avoids uncontrolled motion of a leaflet.
This object is achieved in accordance with the invention in a packaging machine of the above-mentioned kind in that the stop can be removed from the transport path of the tong-like holder into a non-operating position. In this manner, the invention causes the tong-like holder to open and release the leaflet only if a folding box is actually present in the folding box chain. If there is no folding box, the stop is moved out of the transport path of the tong-like holder such that the tong-like holder and leaflet pass by the stop without opening. The stop then returns to its operating position for opening the next tong-like holder when a folding box is present in the folding box chain. In this fashion, the leaflet is released only if it can be inserted into a folding box to prevent uncontrolled release of the leaflets within the transfer device.
If there is no folding box in the folding box chain proximate the transfer device, the leaflet is transported further in the tong-like holder and removed in a defined manner therefrom at a downstream station, preferably disposed at the lower side of the packaging machine, i.e. in the lower transport region of the circulating leaflet transport device.
In a further development of the invention, a sensor means is provided for detecting the presence of a package at the transfer device and for generating a control signal to bring the stop into the non-operating position when no package is present. The sensor means may be an optical or mechanical sensor of conventional design which can reliably detect whether or not a folding box is present in the predetermined section of the folding box chain. In dependence upon said detection, the stop either remains in its operating position within the transport path to open the tong-like holders or it is laterally removed from the transport path into the non-operating position.
In a preferred embodiment of the invention, the stop is biased into its non-operating position by a spring, such that activation of a controllable actuating device is required to move the stop, in opposition to the spring bias, into the operating position and for keeping it there as long as the presence of a folding box is determined by the sensor device. The actuating device is preferably an adjustable pneumatic or hydraulic cylinder.
The stop can be displaced transverse to the transport direction of the chains. In a particularly simple and robust embodiment, the stop is borne for pivoting.
In order to be able to use and adapt the packaging machine to products of different sizes, the stop is preferably adjustable along the transport path of the tong-like holders. This can, in particular, be effected by disposing the stop, together with the spring generating the spring bias and the actuating device, on a displaceably supported slide which can be adjusted, preferably via a chain or a toothed belt in cooperation with an adjustment spindle.
In a preferred manner, the leaflets which remain in an unopened tong-like holder and which are transported through the transport device are removed at a downstream station. Towards this end, a further, in particular stationary remote stop, i.e. disposed downstream of the transfer device, is provided for opening the tong-like holder. If the holder transports a leaflet, the leaflet is removed at this point and transported via a further transport device, e.g. a belt or roller conveyor, away from the transport path of the circulating chains and fed to a container.
The tong-like holder must be kept open by the stop for a sufficiently long period of time to guarantee safe removal of the leaflet from the tong-like holder during insertion of the product. With rapidly working packaging machines, the stop must therefore generally have a length in the transport direction of the chains which is greater than the distance between two adjacent tong-like holders. If such a stop is brought into its non-operating position, several tong-like holders could inadvertently remain closed. In a further development of the invention, this is prevented in that the stop comprises a plurality of stop parts disposed one after the other in the transport direction of the tong-like holders which can be adjusted, independently of one another, between the operating and non-operating positions. The length of each stop part, in the transport direction of the tong-like holders, is therefore less than the spacing between adjacent holders to thereby guarantee that each stop part can return to its operating position as soon as a holder which is to remain closed has passed by and before the next holder reaches that stop part. Corresponding control of the individual stop parts is achieved by sensor means which detect the current position of the holder and which act on the independent actuating means associated with each stop part.
Further details and features of the invention can be extracted from the following description of an embodiment with reference to the drawings.